This model 2 described in the supplement of the article below. It is parameterized for the WT at 24°C. To reproduce figure 6 the results have to be rescaled to circadian time by multiplying time by 24/ tau , with tau being the period of the free-running oscillator. For the wild-type parameter set tau is equal to 22.7149. Article: Isoform switching facilitates period control in the Neurospora crassa circadian clock. Akman OE, Locke JC, Tang S, Carré I, Millar AJ, Rand DA. Mol Syst Biol. 2008;4:164. Epub 2008 Feb 12. PMID: 18277380 , doi: 10.1038/msb.2008.5 Abstract: A striking and defining feature of circadian clocks is the small variation in period over a physiological range of temperatures. This is referred to as temperature compensation, although recent work has suggested that the variation observed is a specific, adaptive control of period. Moreover, given that many biological rate constants have a Q(10) of around 2, it is remarkable that such clocks remain rhythmic under significant temperature changes. We introduce a new mathematical model for the Neurospora crassa circadian network incorporating experimental work showing that temperature alters the balance of translation between a short and long form of the FREQUENCY (FRQ) protein. This is used to discuss period control and functionality for the Neurospora system. The model reproduces a broad range of key experimental data on temperature dependence and rhythmicity, both in wild-type and mutant strains. We present a simple mechanism utilising the presence of the FRQ isoforms (isoform switching) by which period control could have evolved, and argue that this regulatory structure may also increase the temperature range where the clock is robustly rhythmic. This model originates from BioModels Database: A Database of Annotated Published Models. It is copyright (c) 2005-2009 The BioModels Team. For more information see the terms of use . To cite BioModels Database, please use Le Novère N., Bornstein B., Broicher A., Courtot M., Donizelli M., Dharuri H., Li L., Sauro H., Schilstra M., Shapiro B., Snoep J.L., Hucka M. (2006) BioModels Database: A Free, Centralized Database of Curated, Published, Quantitative Kinetic Models of Biochemical and Cellular Systems Nucleic Acids Res., 34: D689-D691.
Centre for Systems Biology at Edinburgh, The University of Edinburgh, Edinburgh, UK